600 Days Without a 3% Daily Change

It’s been a long time now since the S&P 500 had a big change in a single day. You have to go back to November of 2011 to find the last day that the S&P 500 rose or fell by 3% in one day. Since 1950 there have been 200 trading days out of 16,202 in which the S&P changed by 3% or more, which implies that we get one 3% day for every 81 days.

The current streak has lasted 623 trading days, which is the 6th longest period without a big change in the last 65 years. From the history, it looks like most past streaks either fell just short of the 600 day range or pushed through to the 900 day area. If we go that long until there is another 3% day, the next large advance or decline would come in 2015 or 2016. For reference, at these levels a 3% change on the Dow would be a 500 point swing.

With the VIX down at eleven, 623 trading days may be just long enough for us to forget that moments of high volatility are a normal part of securities markets. We’ve gone a long time without a real surprise, but surprises do happen.